Scanning
Use the scan
method to implement scanning of the
Canvas:
$canvas->scanMark(x,
y); $canvas->scanDragto(x,
y);
The first call,
$canvas->scanMark(
x,
y
)
, records the x and y coordinates and
the current Canvas view. The second call,
$canvas->scanDragto(
x,
y
)
, causes the view in the Canvas to be
adjusted by 10 times the difference between these coordinates and the
previous ones sent with scanMark
. This makes the
Canvas look as if it were moved at high speed.
Scrolling Methods
The Canvas widget can be scrolled both horizontally and vertically.
The methods xview
and yview
are
used to communicate with the Scrollbars. See Chapter 6 for more information on how these methods
work.
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